Control valve

ABSTRACT

A control valve having a valve block with a plurality of passages opening to the surface of the valve block and a coacting shoe rockable relative to the surface of the valve block, a flexible band valve member disposed between the shoe and the valve block and connected at one of its ends to the shoe and the other end to the valve block, a force exerting structure connected to the shoe for urging the shoe towards the valve block with a part of the flexible band captured therebetween and for tensioning the flexible band, and means for setting the position of the shoe relative to the valve block to control the extent to which the flexible band valve member uncovers openings in the valve block surface.

United States Patent [191 Hutson et al.

[[111 3,902,525 1451 Sept.2, 1975 CONTROL VALVE [52] US. Cl. l37/625.28; 25l/DlG. 2; l37/625.44 [51] Int. Cl. F16K 11/02 [58] Field of search l37/625.-28, 625.30, 625.44; 251/DIG. 2

.I ""'i n g, MI I [56] References Cited UNITED STATES PATENTS Hayne'r l37/625.28

Primary Examinerl-lenry T. Klinksiek Attorney, Agent, or Firm-Wegner, Stellman, McCord, Wiles & Wood [5 7] ABSTRACT A control valve having a valve block with a plurality of passages opening to the surface of the valve block and a coacting shoe rockable relative to the surface of the valve block, a flexible band valve member disposed between the shoe and the valve block and connected at one of its ends to the shoe and the other end to the valve block, a force exerting structure connected to the shoe for urging the shoe towards the valve block with a part of the flexible band captured therebetween and for tensioning the flexible band, and means for setting the position of the shoe relative to the valve block to control the extent to which the flexible band valve member uncovers openings in the valve block surface.

10 Claims, 4 Drawing Figures PATENTED SEP 2 I975 SHEET 1 [1F 2 sumzufz coNTRoL VALVE This invention pertains to a control valve and, more particularly, to a positive tension band valve usable for controlling fluid flow and, more particularly, for controlling flow to a turbine nozzle plenum.

The Meyersberg U.S. Pat. No. 806,692 discloses a valve mechanism for controlling the flow of steam wherein a flexible band is associated with a valve block having a curved surface. The structure of this patent does not provide for accurate, positive control of the position of the flexible band relative to openings in the valve block and even peeling of the band from the valve block.

Additional patents showing valves using flexible bands are Steele U.S. Pat. No. 1,138,994 and Share U.S. Pat. No. 2,180,173. These patents show flexible bands variable wound around a roller which moves relative to a perforate body to control fluid flow through the latter. These patents do not show a construction wherein the flexible band is maintained under positive tension in all positions and with structure for accurately controlling the relation of the flexible band to the passages. The curvature of the band varies in different positions of operation because of variable layers of the flexible band wound on the roller.

SUMMARY The control valve disclosed herein provides for accu rate control of fluid flow by means of an inextensible flexible band associated with a valve block and a coacting shoe with the band disposed linearly in all positions and under tension for a controlled positioning relative to the valve block and smooth peeling of the flexible band from the valve block as flow through the valve is increased.

More particularly, the valve block and shoe have adjacent surfaces with one of the surfaces being convexly curved to provide for a rocking action of one with respect to the other and with the band disposed therebetween and having one end connected to the valve block and the other end connected to the shoe, with means exerting a force on the shoe to both urge the shoe toward the valve block and place the band in tension and for positioning the shoe relative to the valve block to control the length of the band which engages the sur face of the valve block and thus control the number of flow passage openings at the surface of the valve block which are exposed for flow of fluid therethrough.

In a preferred embodiment, the force exerting means referred to in the preceding paragraph includes a cable connected to an end of the shoe opposite from the end of the shoe to which the flexible band is connected and with both the shoe and valve block having convexly curved surfaces to have parts of the band length wrapped both against the valve block surface and the shoe surface and with undercut channels ofa radii less than the surfaces in both the shoe and valve block in which said cable is positioned whereby yieldable means pulling on said cable urges the shoe toward the valve block in all positions of the shoe and also maintains positive tension on the flexible band to have a part of the shoe surface engage and press the band against the valve block and have the shoe maintain firm, full-width contact with the flexible band. As the shoe is rocked along the length of the valve block in one direction, the

flexible band is uniformly peeled from the valve to accurately increase the rate of fluid flow through the valve block.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a central, vertical section of the control valve showing the operative components in one position thereof;

FIG. 2 is a fragmentary view, similar to FIG. 1 showing the operative components in a different operating position;

FIG. 3 is a section, on an enlarged scale, taken generally along the line 3-3 in FIG. 1; and

FIG. 4 is a fragmentary view, on an enlarged scale, taken along the line 4-4 in FllG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT The control valve has a generally cylindrical body 10 with suitable end walls, one of which is shown at 12, to define a sealed enclosure and having an inlet opening 11 in the end wall 12 for receiving fluid, such as steam, for delivery to a turbine nozzle plenum.

A valve block 15 is positioned within the valve body and mounted to end wall 12 and has a series of exit ports 16 connected by passage structure including passages 17 in the end wall 12 for delivery of the fluid to a device, such as a turbine nozzle plenum, and in an amount determined by the control valve. Each of the exit ports has a length to intersect with a plurality of passages 20 extending to a surface 21 of the valve block. As shown, particularly in FIG. 4, there are four pairs of flow passages 20 communicating with an exit port 16 and with the flow passages grouped whereby the openings of the flow passages at the surface 21 of the valve block are arranged with two pairs of openings to either side of a longitudinal centerline of the valve block surface.

An elongate shoe is positioned adjacent the valve block 15 with a surface 31 thereof facing the surface 21 of the valve block.

A valve member 35, in the form of a flexible, inextensible band formed of a material such as flexible metal, coacts with the valve block 15 to control the number of flow passages 20 that are opened to the interior of the valve body to receive fluid and provide for delivery thereof to the associated exit ports 16. The flexible band 35 has a linear extent, with one of its ends secured adjacent an end of the valve block 15 by attachment means 36. The other end of the flexible band is attached to an end of the shoe 30 by suitable attachment means 37. The flexible band 35 has a width to span substantially the entire lateral extent of surface 21 of the valve block 15 and therefore the entire lateral disposition of passage openings leading to an exit port.

The shoe 30 has its surface 31 convexly curved in order that the surface may roll along and rock relative to the valve block 15 as the shoe is moved between the positions shown in FIGS. 1 and 2. Additionally, the sur face 21 of the valve block is convexly curved, with the result that the flexible band 35 in all of its control positions relative to the valve block 15 has part of its length wrapped about a portion of the length of the valve block surface 21 and another part of its length wrapped onto the surface 31 of the shoe.

By means to be described subsequently, the shoe 30 in all positions thereof is urged toward the valve block 15 with a portion of the flexible band 35 positioned between the shoe surface 31 and the surface 21 of the valve block and as shown in FIG. 3. This assures full width contact of the flexible band 35 with the valve block surface at the location where the flexible band changes from contact with the shoe into contact with the valve block. The aforesaid means also places positive tension on the flexible band to have the flexible band firmly wrapped onto the surface 21 of the valve block. The above conditions provide for even peeling of the flexible band from the valve block surface as the shoe moves from the position of FIG. 1 toward the position of FIG. 2.

The means for exerting a force on the shoe and controlling the position thereof with respect to the valve block includes a flexible cable 40 of a suitable wire material having an end connected by suitable means 41 to an end of the shoe 30 opposite from the shoe end which is connected to the flexible band 35. Tensioning structure, indicated generally at 42, exerts a yieldable pulling force on the cable 40. The positioning of the shoe is controlled by a linkage having pivotally interconnected arms 45 and 46, with the arm 45 fixed to an input shaft 47 extending to a location exteriorly of the valve body for rotatable positioning to set the control position of the valve. The arm 46 has a pivot pin 48 mounted to the shoe 30. As the input shaft 47 is rotated counterclockwise from the position of FIG. 1, the shoe in coaction with force exerted by the cable 40 is caused to rock along the valve block toward the position of FIG. 2.

The cable 40 functions to maintain the flexible band 35 in tension and urge the shoe 30 toward the valve block 15 in all positions thereof by having the cable positioned within channels 50 and 51 of the valve block and shoe, respectively. The bases of these channels are convexly curved and of a radius less than the adjacent surfaces 21 and 31 of the valve block and shoe and against which the flexible band 35 engages. This relation, along with the location of the tensioning structure 42 to assure that a part of the cable 40 is in engagement within the channel 50 of the valve block 15 in all positions of the shoe and flexible band 35, assures the applization of the necessary force in all positions of the shoe.

The flexible band 35 has a major part of its length in- :ermediate the ends thereof slotted as seen in FIGS. 1 and 3, to provide laterally separated lengths 35a and 35b and a space whereby the cable 40 can make the :ransition between association with the channel 50 of :he valve block and channel 51 of the shoe 30. In the )osition of FIG. 3, the cable 40 is shown in transition md generally coplanar with the flexible band 35 and is )artially within the channels of both the valve block md shoe.

The tensioning structure 42 has a casing 60 mounted o and in sealed communicating relation with the valve )ody 10 with an internal chamber receiving an end 61 )f the cable which is connected to a piston 62. Means 11'6 provided within the casing 60 for exerting a resilent pull on the cable 40. This means may be a pres- ;ure-exerting fluid medium or, as shown, a spring 63 )ositioned within the casing and acting against the pison 62. As mentioned previously, the tensioning strucure 42 is mounted to the body 10 at a location vhereby the cable 40 is caused to have some degree of vrap within the channel 50 of the valve block 15 in all positions of the control valve member structure whereby a force is always exerted urging the shoe 30 toward the valve block and maintaining the flexible band 35 in tension.

The valve components are shown in FIG. 1 positioned to block fluid flow to all of the exit ports 16. A controlled amount of fluid flow to one or more of the exit ports 16 can then be established by counterclockwise rotation of the input shaft 47 toward an opposite limit position shown in FIG. 2. In movement from the position of FIG. 1 to that of FIG. 2, the shoe surface 31 rolls along the flexible band 35 to increase the wrap of the band on the surface 31 of the shoe and to provide progressive accurate full width peeling of the flexible band from the surface 21 of the valve block. The actual line of contact of the flexible band with the surface 21 of the valve block is controlled by a part of the surface 31 of the shoe engaging the flexible band against the valve block surface and with this part of the shoe surface varying as the shoe rolls along the flexible band and increases the wrap thereof on the shoe surface to the extent shown in FIG. 2. There is a positive peeling of the flexible band across its entire width as the shoe 30 rocks toward the position of FIG. 2. Thus, the position of the input shaft 47 accurately controls the position of the shoe 30 relative to the valve block 15 and the rate of flow to the flow passages 20 is accurately established.

While the invention is illustrated with a showing of a single band controlled by a single cable, it should be understood that there may be other arrangements such as another tension member in lieu of the cable, or a plurality of cables actuating a single band or several bands.

We claim:

1. A control valve having a valve block with a plurality of flow passages with openings to a convexly curved surface of the valve block, a valve member in the form of a flexible band having one end connected adjacent one end of the valve block and having length and width dimensions to overlie all of said openings, a shoe with a convexly curved surface engageable with said band at a side thereof opposite a side which engages the valve block, means connecting the other end of said band to an end of said shoe, means for setting the position of said shoe to control the position of the band relative to the valve block openings, and means for exerting a force on said shoe which places said band in tension lengthwise thereof and which urges said shoe toward said valve block with the band positioned between the convexly curved surfaces thereof.

2. A control valve as defined in claim 1 wherein said force exerting means includes a cable connected to said shoe at an end thereof opposite to said end of the shoe which is connected to said band, and means for exerting a pull on said cable.

3. A control valve as defined in claim 1 wherein each of said shoe and valve block have a convexly curved channel recessed inwardly from the convexly curved surface, and said force exerting means includes a cable connected to an end of said shoe opposite the end of the shoe connected to the band and said cable being positioned part in the channel of each of the valve block and shoe, and means for exerting a pull on said cable.

4. A control valve as defined in claim 3 wherein said pull exerting means is positioned to have a part of said cable in said valve block channel in all positions of said shoe and band.

5. A control valve as defined in claim 4 wherein said band has a lengthwise slot for a major part of its length and with said cable passing through said slot.

6. A control valve as defined in claim 1 wherein said band engages in part said surface of the valve block and in part said surface of said shoe, and said force exerting means includes a tensioned cable connected to shoe and engageable in part with 'said valve block and in part with shoe along curved lines of contact of a lesser radius than said surfaces.

7. A control valve having a valve block with a series of passages each having an opening to a convexly curved surface of the valve block, a shoe with a convexly curved surface facing said curved surface of the valve block, a valve member in the form of an inextensible flexible band having one end operatively connected to the valve block and the other end connected adjacent an end of the shoe whereby the band is positioned between the valve block and shoe surfaces and partly engages the shoe and the valve block, means for exerting a force on said shoe which urges said surfaces toward each other with the band therebetween and which places said band in tension and including means for rocking said shoe relative to said valve block to vary the length of wrap of the band on said shoe and valve block and vary the number of openings covered by the band.

8. A control valve as defined in claim 7 wherein said openings are in a series of laterally spaced pairs along the curved surface of the valve block, said band has a slot along its length, and said force exerting means comprises a cable connected to said shoe at an end thereof remote from the connection of the band to the shoe and passing through the slot to engage the shoe along part of the cable length and to engage the valve block along part of the cable length.

9. A control valve as defined in claim 8 wherein said cable engages both said shoe and valve block along curved parts thereof of radii less than said surfaces of said shoe and valve block.

10. A control valve having a. valve block with a series of passages each having an opening to a surface of the valve block, a shoe with a surface facing said surface of the valve block and having a length approximately the length of the valve block surface, at least one of said surfaces being convexly curved, a valve member in the form of an inextensible flexible band having one end operatively connected to the valve block and the other end connected adjacent an end of the shoe whereby the band is at all times linearly extended between the valve block and shoe surfaces and has part of its length en gaging the valve block and part of its length engaging the shoe, means for exerting a force on said shoe which urges said surfaces toward each other with the band therebetween and which places said band in tension and including means for rocking ing said shoe relative to said valve block to vary the length of engagement of the band on said shoe and valve block and vary the part of the shoe engaging the band against the valve block whereby the exposure of openings by the band may be controlled.

* =l= =l l 

1. A control valve having a valve block with a plurality of flow passages with openings to a convexly curved surface of the valve block, a valve member in the form of a flexible band having one end connected adjacent one end of the valve block and having length and width dimensions to overlie all of said openings, a shoe with a convexly curved surface engageable with said band at a side thereof opposite a side which engages the valve block, means connecting the other end of said band to an end of said shoe, means for setting the position of said shoe to control the position of the band relative to the valve block openings, and means for exerting a force on said shoe which places said band in tension lengthwise thereof and which urges said shoe toward said valve block with the band positioned between the convexly curved surfaces thereof.
 2. A control valve as defined in claim 1 wherein said force exerting means includes a cable connected to said shoe at an end thereof opposite to said end of the shoe which is connected to said band, and means for exerting a pull on said cable.
 3. A control valve as defined in claim 1 wherein each of said shoe and valve block have a convexly curved channel recessed inwardly from the convexly curved surface, and said force exerting means includes a cable connected to an end of said shoe opposite the end of the shoe connected to the band and said cable being positioned part in the channel of each of the valve block and shoe, and means for exerting a pull on said cable.
 4. A control valve as defined in claim 3 wherein said pull exerting means is positioned to have a part of said cable in said valve block channel in all positions of said shoe and band.
 5. A control valve as defined in claim 4 wherein said band has a lengthwise slot for a major part of its length and with said cable passing through said slot.
 6. A control valve as defined in claim 1 wherein said band engages in part said surface of the valve block and in part said surface of said shoe, and said force exerting means includes a tensioned cable connected to shoe and engageable in part with said valve block and in part with shoe along curved lines of contact of a lesser radius than said surfaces.
 7. A control valve having a valve block with a series of passages each having an opening to a convexly curved surface of the valve block, a shoe with a convexly curved surface facing said curved surface of the valve block, a valve member in the form of an inextensible flexible band having one end operatively connected to the valve block and the other end connected adjacent an end of the shoe whereby the band is positioned between the valve block and shoe surfaces and partly engages the shoe and the valve block, means for exerting a force on said shoe which urges said surfaces toward each other with the band therebetween and which places said band in tension and including means for rocking said shoe relative to said valve block to vary the length of wrap of the band on said shoe and valve block and vary the number of openings covered by the band.
 8. A control valve as defined in claim 7 wherein said openings are in a series of laterally spaced pairs along the curved surface of the valve block, said band has a slot along its length, and said force exerting means comprises a cable connected to said shoe at an end thereof remote from the connection of the band to the shoe and passing through the slot to engage the shoe along part of the cable length and to engage the valve block along part of the cable length.
 9. A control valve as defined in claim 8 wherein said cable engages both said shoe and valve block along curved parts thereof of radii less than said surfaces of said shoe and valve block.
 10. A control valve having a valve block with a series of passages each having an opening to a surface of the valve block, a shoe with a surface facing said surface of the valve block and having a length approximately the length of the valve block surface, at least one of said surfaces being convexly curved, a valve member in the form of an inextensible flexible band having one end operatively connected to the valve block and the other end connected adjacent an end of the shoe whereby the band is at all times linearly extended between the valve block and shoe surfaces and has part of its length engaging the valve block and part of its length engaging the shoe, means for exerting a force on said shoe which urges said surfaces toward each other with the band therebetween and which places said band in tension and including means for rocking ing said shoe relative to said valve block to vary the length of engagement of the band on said shoe and valve block and vary the part of the shoe engaging the band against the valve block whereby the exposure of openings by the band may be controlled. 